Hydrocarbon oil conversion



1934- ,D. F. GERSTENBERGER 1,945,604

HYDROCARBON OIL CONVERSION Filed April 4, 1932 INVENTOR DONALD F.GERSTENBERGER BY 7 fl ATT NEY KMZMUUE Patented Feb. 6, 1934 f 1,945,604

----.--------UNITED STATES PATENT OFFICE HYDROCARBON 01L CONVERSIONDonald F. Gerstenberger, Chicago, Ill.', assignor to Universal OilProducts Company, Chicago, 111., a corporation of South DakotaApplication April 4, 1932. SerialNo. 602,904

\3 Claims. (01. 196-60) This invention relates to the conversion ofhypreferably so proportioned to give substantially drocarbon oil, andmore particularly refers to the same total vapor time that would beobtained improvements in the type of cracking process in the ordinarytype of single vapor-phase reacand apparatus wherein the hydrocarbonoilissubtion chamber but giving an increased vapor vejectedtoconversionconditions of elevated temlocity. High vapor velocity alonehas been 60 perature and substantial superatmospheric presknown todecrease the deposition of coke and, sure in a heating element, followedby 0011- as here used, in combination with the quick retinuedconversion, at superatmospheric pressure, moval of coke-forming residualliquids at various particularly of the vaporous materials resulting.stages during the treatment, will, under the propfrom the heattreatment, quick separation of er temperature and pressure conditionsfor the 65 residual liquid from the vapors and further vaparticular oilbeing treated, substantially elimporization of the latter at reducedpressure. inate coke deposition in the reaction zone and in Theimprovements of the present invention many cases will even permit theuse of an inare particularly concerned with the'quick separacreasedconversion temperature without increastion from the vapors and removalfrom the reing the coke and gas formation, thereby material 70 actionzone of residual liquid conversion prodly improving the anti-knock valueof the finished ucts during the conversion time in the reaction motorfuel product of the system. zone following the heating element and com-The attached diagrammatic drawing illusprise methods and means ofremoving said residtrates one specific form of apparatus incorporat ualliquid products at various stages during this ing the features of thepresent invention and in 75 continued conversion time instead ofremoving which the process of the invention may be sucthe total residualliquid products together with cessfully practiced. Raw oilcharging stockmay the vapors from the reaction zone. In this manbe supplied throughline 1 and valve 2 to pump ner the residual liquid issubjected to muchshort- 3 from which it may be fed through line 4 and er conversion timethan the vapors. The advanvalve 5 to heating element 6. When desired, a80 tages of short liquid conversion time and proportion or all of theraw oil may pass from pump longed vapor conversion time are suflicientlywell 3 through line 7 and valve 8 into fractionator known to require noexplanation or justification 9 wherein it comes into direct andcounterhere. current contact with the cracked vapors, serving Onespecific manner in which the advantages to partially cool the latter andassist their fracas of the concepts of the present invention may betionation and being thereby preheated. The obtained comprises utilizinga plurality of elonrelatively heavy components .of the vapors are gatedvertical reaction chambers connectedinsecondensed in the fractionatorand collect, tories,heated conversion products from the heating getherwith the preheated raw oil, in the lower element of the system enteringthe upper porportion thereof, from which they are withdrawn tion of thefirst reaction chamber, vapors from through line 10 and valve 11 to pump12. The the lower portion of each chamber passing to the refluxcondensate or reflux condensate and preupper portion of the succeedingchamber and reheated raw oil from factionator 9 is directed sidualliquid being withdrawn from the lower from pump 12 through line 13 andvalve 14 into 40 portion of each chamber. In the last chamber line 4,commingling therein with the raw oil, of the series the residual liquidformed in this or that portion, if any, supplied directly to line zonemay be withdrawn therefrom separately or 4 from pump 3, and passingtherewith to heating together with the final vaporous product fromelement 6. g g the entire series and, in the preferred embodi- Heatingelement 6 is located in a furnace 15 of 45 ment of the invention, bothvaporous and liquid any desired form suitable for supplying thereproducts from the reaction zone are discharged quired heat to the oilundergoing conversion. into a reduced pressure vaporizing chamber al-The heated oil is discharged from heating elethough, when desired, thevaporous products may ment 6 through line 16 and valve 17. into the passfrom the reaction zone directly to fractionaupper portion of reactionchamber 18.

50 tion while the residual liquids removed from Chambers 18, 19'and 20are similar reaction each reaction chamber are commingled and subzoneswherein conversion of the vaporous prodjected to further vaporization atreduced presucts may continue for a predeterminedtime while sure. In thearrangement above described, any the residual liquid products areremoved therenumber of a plurality of reaction chambers may from withoutbeing subjected to extensive further 55 be employed, their diameter andheight being conversion time. Products from heating element 6 passdownward through chamber 18, The unvaporized liquid which enters thiszone and the residual liquid formed during passage of the materialsthrough this chamber are withdrawn from its lower portion through line21 and valve 22. vaporous products separately withdrawn from chamber 18pass through line 23 into the upper portion of chamber 19, passingdownward through this zone. The residualliquid formed in chamber 19 iswithdrawn from its lower portion through line 24 and valve 25 while thevaporous products are separately withdrawn through line 26 and enter theupper portion of chamber 20, passing downward therethrough. The residualliquid formed in chamber 20 is withdrawn from its lower portion throughline 27 and valve 28. The vapors from chamber 20, which comprise thetotal conversion products remaining in vaporous form at this state ofthe process, may be handled in any one or any combination of severalmanners. They may be separately withdrawn from the lower portion ofchamber 20 through line 29 and may pass through line 30 and valve 31directly to fractionator 9, or they may be directed, all or in part,through valve 32, in line 29, into line 33 and thence to reducedpressure vaporizing chamber 35 or, when desired, all or any portion ofthe vapors may be withdrawn from chamber 20, together with the residualliquid formedin this zone, through line 27 and valve 28. The residualliquids from each of the chambers are commingled in line 33- and passthrough valve 34 into reduced pressure vaporizing chamber 35. In caseall or any portion of the vapors from chamber 20 pass eitherthrough line27 and valve 28 or through line 29 and valve 32 into line 33, theycommingle therein with the residual liquid products and pass therewithto chamber 35, serving to further heat these products and assist theirvaporization at reduced pressure.

Residual liquid remaining unvaporized in chamber 35 may be withdrawntherefrom through line 36 and valve 37 to cooling and storage or to anydesired further treatment. Vapors from chamber 35 pass through line 38and valve 39 into fractionator 9 which, in the case illustrated, is thesame fractionator to which vaporous products from chamber 20 aredirected, in case they are not first commingled with the residualliquid.

The heavy components of the vapors supplied to fractionator 9 arecondensed by fractionation in this zone, passing therefrom, as alreadydescribed, to heating element 6 for further conversion. The lightcomponents of the vapors re- -maining uncondensed within thefractionator are withdrawn from the upper portion thereof through line40 and valve 41, are subjected to condensation and cooling in condenser42, distillate and uncondensable gas from which are directed throughline 43 and valve 44 to collection in receiver 45. Uncondensable gas maybe released from receiver 45 through line 46 and valve 4'7. Distillatemay be withdrawn from the tially reduced pressure of the order of 100pounds down to substantially atmospheric may be employed in thevaporizing chamber and the pressure in the succeeding fractionating,condensing and collecting portions of the cracking system may besubstantially equalized therewith. The conversion temperature employedat the outlet from the heating element may range, for example, from 850to 1,000 F.

The following examples of specific operating conditions and resultsobtainable by their use are given for the purpose of more clearlyillustrating the features and advantages of the presentvinvention.Let'us first consider a cracking operation such as that aboveillustrated and described except that only one high pressure reactionchamber is employed, products from the heating element entering itsupper portion'while both vaporous and liquid products are simultaneouslywithdrawn from the lower portion of the chamber and directed to thereduced pressure vaporizing chamber. The rawoil charging stock suppliedto this system is a blend of Pennsylvania naphtha and fuel oil having agravity of approximately 43 A. P. I. A temperature of about 925 F. isemployed at the outlet from the heating element and a pressure of about350 pounds is utilized in the heating element and reaction chamber. Thepressure in the vaporizing chamber is reduced to approximately 50 poundsper square inch. This operation may yield, per barrel of charging stock,about of motor fuel having an octane number of approximately 73 andabout 6% of heavy residual oil having a gravity of about 4 A. P. I. Thegas production is less than 400 cubic feet per barrel of charging stock,but the total coke, gas and loss is approximately 14% In anotheroperation utilizing the same charging' stock and the same type ofoperation, with the exception that the features of the present inventionare utilized by employing three reaction chambers such as illustratedand above described; the reaction chambers are substantially the samelength as the single reaction chamber utilized in the above operationand the cross-sectional area of each is approximately one-third of thatof the single reaction chamber, thus giving substantially the same vaporreaction time and about three times the vapor velocity through thereaction zone. In this operation the temperature of the oil leaving theheating element is increased to approximately 935 F. The yield ofgasoline recovered by this operation is substantially the same(approximately 80% of the charging stock) and its anti-knock value isincreased to an octane number of approximately 78. About 10% of residualoil of improved quality may be recovered and the production of gas isslightly increased but, owing to the decreased formation of coke in thereaction zone and the negligible deposition of this material in thereaction chambers, the operating time is greatlyprolonged over thatpossible in the first operation described.

I claim as my invention:

1. A hydrocarbon ofl cracking process which comprises heating the oil tocracking temperature under pressure while flowing in a restricted streamthrough a heating zone, discha ging the heated oil into the upperportion of an unheated vertically elongated reaction zone maintainedunder cracking conditions of temperature and pressure, passing thevapors and unvaporized oil downwardly through the reaction zone andseparately removing the vapors and unvaporized oil from the lowerportion of the reaction zone, in- 1 troducing the vapors to the upperportion of a second vertically elongated reaction zone maintained undercracking conditions of temperature and pressure, passing the vaporsdownwardly through the second reaction zone and removing the same fromthe lower portion thereof, passing the unvaporized oil withdrawn fromthe first-mentioned reaction zone and such liquid constituents as areformed in the second reaction zone to a vaporizing zone maintained underlower pressure than the reaction zones and distilling the same therein,supplying the vapors evolved in the vaporizing zone and the vaporswithdrawn from the second reaction zone toa common fractionating zoneand fractionating the admixed vapors therein, retuming resultant refluxcondensate to the heating zone for recycling through the process, andfinally condensing the fractionated vapors.

2. A hydrocarbon oil cracking process which comprises heating the oil tocracking temperature under pressure while flowing in a restricted streamthrough a heating zone, discharging the heated oil into the upperportion of an unheated vertically elongated reaction zone maintainedunder crack ing conditions of temperature and pressure, passing thevapors and unvaporized oil downwardly through the reaction zone andseparately removing the vapors and unvaporized oil from the lowerportion of the reaction zone, introducing the vapors to the upperportion of a second vertically elongated reaction zone maintained undercracking conditions of temperature and pressure, passing the vaporsdownwardly through the second reaction zone and removing the same fromthe lower portion thereof, subsequently combining the vapors with theunvaporized oil withdrawn from the first-mentioned reaction zone andintroducing into vapors and residue in the vaporizing zone,

fractionating the last-mentioned vapors to condense heavier fractionsthereof and returning resultant reflux condensate to the heating zone,

and flnally condensing the fractionated vapors.

3. In a hydrocarbon oil cracking process of the character wherein theoil is heated to cracking temperature under pressure while flowing in arestricted stream through a heating zone, the vaporous and liquid oilthence passed downwardly through an unheated vertically elongatedreaction zone, the liquid oil withdrawn from the lower portion of thereaction zone and flash distilled in a vaporizing zone by pressurereduction; the improvement which comprises separately removing vaporsfrom the lower portion of the reaction zone and passing the same througha series of vertical vapor reaction zones maintained under crackingconditions of temperature and pressure, introducing the vapors to theupper portion of each of the vapor reaction zones to flow downwardlytherethrough and removing the vapors from'the lower portion of each ofthe vapor reaction zones, introducing liquid constituents formed in thevapor reaction zones to said vaporizing zone, combining the vaporswithdrawn from the last vapor reaction zone of the series with thevapors evolved in the vaporizing zone, fractionating the vapor mixtureLto condense heavier fractions thereof and returning resultant refluxcondensate to the heating zone, and finally condensing the fractionatedvapors.

DONALD F. GERSTENBERGER.

